1990/05/21 Caterpillar

New Valve Shield Used To Control Oil Slobber {1105}

Usage:

3176 Truck Engines

Description of Change: A new valve shield is used which prevents excessive oil slobber during engine idle. The new shield is available either by itself, or preassembled onto the rotocoil. See Illustrations 1 and 2 for the location of the new shield.

Adaptable To: The new 7E7978 Shield is part of the 9Y2760 Basic Cylinder Head Group. If obtained by itself, the smaller diameter of the shield will snap in place into the bottom side of the existing rotocoil. The shield may also be obtained as an assembly. The 7E7977 Rotocoil Assembly contains both the 7C8581 Rotocoil Assembly and the new 7E7978 Shield. See Illustration 2. This change is effective with 3176 (2YG3870) Truck Engine, and is adaptable to first production.

Illustration 1. Cross section of inlet and exhaust valves showing the new shield.

Illustration 2. 7E7977 Rotocoil Assembly. (1) Rotocoil assembly. (2) New shield.

Caterpillar Information System:

1990/05/21 Some 4C4462 Sleeve Removal And Installation Groups For Unit Injectors May Contain 4C5562 Reamer Assemblies That Are Dimensionally Incorrect {0782,1290}

1990/05/21 Check New 1W7578 And Remanufactured OR2530 Crankshafts For Burr On Thrust Face {1202,1203}

1990/05/14 Parts Service Information For Pistons{1214,1225,1331}

1990/05/14 1U9800 Ultrasonic Wear Indicator Group For Measuring Undercarriage Wear On Track-Type Machines And Thickness Of Other Components{0787,4150}

1990/05/07 New Fuel Injector Group Used On Heavy Fuel Engines {1290}

1990/05/07 Fuel Return Line Added To Fuel System In Power Modules {1274}

1990/05/07 Customer Interface Control Module Available {4490,7400}

1990/04/30 Reconditioning Of Bridge Wear Seat Is Permitted; Will Prevent Bridge Replacement When Not Necessary{1121}

1990/04/30 Data Link Adapter For 3176 And 3406B PEEC (Programmable Electronic Engine Controls) Used In Navistar Trucks{1900}

1990/04/23 Oil Level Gauge (Dipstick) Marks For 3116 Marine Engines{1326}

1990/04/23 New Crankcase Side Cover Use With Centrifugal Oil Filter Group{1328}

1990/04/23 New Rocker Arm Assemblies Have New Inserts And Buttons{1123}

1990/05/21 Governor Springs For Sleeve Metering Fuel Systems {1264}

1990/05/21 New Valve Assembly And Spacer Used In Fuel Transfer Pump Group {1256}

1990/05/21 Some Fuel Injectors May Be Used In Mixed Sets {1290}

1990/05/28 Testing The Starter On The Engine {1453,1450,1401}

1990/05/28 New Fuel System Components For 3176 Truck Engines {1251,1290}

1990/05/28 New Operation And Maintenance Manual For 3306B Truck Engines {0374,0375,1000}

1990/05/28 Improved Manufacturing Process Extends Service Life Of New Exhaust Valves {1105}

1990/05/28 New, Longer Bolt Gives Better Retention To Fuel Injection Lines {1252}

1990/05/28 New Bolt Improves Serviceability Of Auxiliary (Sea Water) Pump Group {1371}

1990/05/28 Oil Guidelines For 3600 Family Of Engines {1318}

1990/06/04 Improved Seals Used; Seal Replacement In Folded Core Radiators{1353}

1990/06/04 New Bolt And Spacer Used In Exhaust Manifold Group To Improve Gasket Retention{1059}